diff --git a/extensions/vscode-api-tests/package.json b/extensions/vscode-api-tests/package.json
index b305d960895..57a6eb0247e 100644
--- a/extensions/vscode-api-tests/package.json
+++ b/extensions/vscode-api-tests/package.json
@@ -26,6 +26,10 @@
 				},
 				"farboo.config4": {
 					"type": "string"
+				},
+				"farboo.get": {
+					"type": "string",
+					"default": "get-prop"
 				}
 			}
 		}
diff --git a/extensions/vscode-api-tests/src/workspace.test.ts b/extensions/vscode-api-tests/src/workspace.test.ts
index 972ad2ebf29..b79ad39be3b 100644
--- a/extensions/vscode-api-tests/src/workspace.test.ts
+++ b/extensions/vscode-api-tests/src/workspace.test.ts
@@ -21,6 +21,10 @@ suite('workspace-namespace', () => {
 		assert.ok(config.has('config0'));
 		assert.equal(config.get('config0'), true);
 		assert.equal(config.get('config4'), '');
+		assert.equal(config['config0'], true);
+		assert.equal(config['config4'], '');
+
+		assert.throws(() => config['config4'] = 'valuevalue');
 
 		assert.ok(config.has('nested.config1'));
 		assert.equal(config.get('nested.config1'), 42);
@@ -28,6 +32,15 @@ suite('workspace-namespace', () => {
 		assert.equal(config.get('nested.config2'), 'Das Pferd frisst kein Reis.');
 	});
 
+	test('configuration, name vs property', () => {
+		const config = workspace.getConfiguration('farboo');
+
+		assert.ok(config.has('get'));
+		assert.equal(config.get('get'), 'get-prop');
+		assert.deepEqual(config['get'], config.get);
+		assert.throws(() => config['get'] = <any> 'get-prop');
+	});
+
 	test('configuration, getConfig/value', () => {
 		const value = workspace.getConfiguration('farboo.config0');
 		assert.equal(Object.keys(value).length, 2);
diff --git a/src/vs/workbench/api/node/extHostConfiguration.ts b/src/vs/workbench/api/node/extHostConfiguration.ts
index 6bf43202bf4..1a91cf5ecf5 100644
--- a/src/vs/workbench/api/node/extHostConfiguration.ts
+++ b/src/vs/workbench/api/node/extHostConfiguration.ts
@@ -61,7 +61,8 @@ export class ExtHostConfiguration extends ExtHostConfigurationShape {
 			}
 			return result;
 		};
-		return result;
+
+		return Object.freeze(result);
 	}
 
 	private static _lookUp(section: string, config: any) {